Blast deflector

ABSTRACT

A blast energy deflector to reduce load and energy transmitted to a vehicle from buried mines or improvised explosive device (IED) threats. The deflector may add stiffness to the hull thereby protecting or delaying deformation or damage to the vehicle underside. The deflector may be hollow, filled with plastic or other composites to dissipate blast energy, or solid, and may be detachably affixed to the vehicle underside.

STATEMENT OF GOVERNMENT INTEREST

This disclosure was made in part with Government support by The UnitedStates Department of the Army. The Government has certain rights in thedisclosure.

TECHNICAL FIELD

This disclosure relates to an energy deflector to reduce load and energytransmitted to any vehicle structure such as a body on frame or amonocoque vehicle structure, or any other vehicle structure, from buriedmines or improvised explosive device (IED) threats. The deflector mayadd stiffness to the hull thereby protecting or delaying deformation ordamage to the vehicle underside. The deflector may be hollow, filledwith plastic or other composites to dissipate blast energy, or solid,and may be detachably affixed to the vehicle underside.

BACKGROUND

Existing combat vehicles are extensively used in conflict theaters whereasymmetric warfare occurs. In such a conflict, it is very effective touse simple weapons to destroy very expensive vehicles and otherequipment. IEDs and buried mines are especially favored by suchasymmetric forces. They are cheap to make, easy to conceal and deliver alarge amount of energy into a small area of a very expensive piece ofequipment. The hulls of any vehicle subjected to an IED or buried mineare damaged and the personnel are injured, or worse. Part of the issueis that the blast from such a device is concentrated upwardly against asmall part of a vehicle, thereby concentrating the destructive effect ofthe impact. Some vehicles have used reinforced hull designs or haveadopted vehicle hull designs calculated to deflect or spread the blastforce over a large area. However, there are many lighter armoredvehicles where such design parameters are not used, or where apre-existing vehicle does not incorporate such a design In addition,vehicles previously designed to withstand blast events from previousIEDs and buried mines now face much more powerful IEDs and buried mines,thereby reducing the protective value of previous designs. Moreover,vehicles with segmented armor plating may be especially susceptible toconcentrated blast force.

Improvements in blast energy deflection are continuing and needed. Inone embodiment, the blast deflector may be a piece of angled weldedplate metal attached to the underside of a vehicle. In other vehicleswith segmented armor, the deflectors may be attached to a channel withfasteners along the length of the vehicle to impart protection over theentire underside of the vehicle. Attachment of the device to the vehicleis not necessarily rigid. The blast deflector includes mounting thedeflector on an energy absorber or spacer to decouple it from the mainvehicle hull structure. The device can remain effective at reducingtransferred energy from a blast event to the hull even if it eventuallyor quickly is separated from the structure and the device works bydirecting energy away from the vehicle early in the blast event. Thestructure and/or stiffness provided by the device can assist inprotecting the structure above it and dispersing the blast energy over agreater area, thereby dissipating it. The device may be flexibly mountedto allow for closer placement to the ground without negatively affectingvehicle mobility.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a vehicle having a hull shape;

FIG. 2A is a cross sectional view of a blast deflector according to oneembodiment;

FIG. 2B is a perspective view of a blast deflector with concave sides;

FIG. 2C is perspective view of a blast deflector with convex sides;

FIG. 3 is a representation of a detail of the underside of a vehiclehull showing an arrangement of apertures to affix the blast deflector tothe vehicle hull;

FIG. 4 is a cross sectional view of a blast deflector according to oneembodiment mounted on a vehicle hull;

FIG. 5 is a cross sectional view of blast deflector according to anotherembodiment mounted on a V shaped hull;

FIG. 6 is a cross sectional view of a blast deflector according to oneembodiment mounted on a bowl shaped vehicle hull;

FIG. 7 is a cross sectional view of a blast deflector mounted onto a Ushaped vehicle hull;

FIG. 8 is a cross sectional view of a blast deflector mounted onto aflat surface vehicle hull; and

FIGS. 9A through 9D are the data from various blast tests showing thebenefits of a blast deflector.

DETAILED DESCRIPTION

All figures and examples herein are intended to be non-limiting; theyare mere exemplary iterations and/or embodiments of the claims appendedto the end of this description. Modifications to system, device, theorder of steps in processes, etc., are contemplated.

Referring to FIG. 1, vehicle 10 is an armored vehicle with a body 12 andan underside 13 having a hull or structure configuration 14 which may beof any shape. In this embodiment, the vehicle structure is depicted asmonocoque, however, it is also appreciated that a vehicle structure maybe the main frame or main body of a vehicle, such as an all terrainvehicle, an armored personnel carrier or a tank, or any other type ofvehicle construction. In the shown embodiment, the vehicle is equippedwith tires 15, which are through axles connected to a drive train forvehicle locomotion. Generally the vehicle underside is designed to havesome blast deflecting ability so that exploding IEDs and buried mines donot incapacitate the crew or disable the vehicle.

FIG. 2A is a cross sectional view of one embodiment of a blast deflector16. The deflector may be made of 6061-T6 steel or other metal, as wellas from extruded alloys such as 5083 and 6063. Aerospace/special alloysare also viable as materials for the blast deflector and may include7075 and 2139. The blast deflector 16 has a substantially triangularshape 18, and may be equilateral, or isosceles in configuration. Indeed,it is contemplated that the blast deflector is of any shape that isconducive to deflection of blast forces, and may be assume the shape ofa triangle. In the embodiments shown, the base 20 of the deflector isconfigured to retrofit an existing vehicle. The sides 22, 24, mayintersect at the apex 24, and may extend beyond the base to form legs 26and 28, respectively. The legs are equipped with apertures 30, 32,respectively, to align with apertures 42 in the vehicle hull, todetachably affix the blast deflector in place on the vehicle structure.In one embodiment, apertures 42 are arranged in parallel rows along theentire length of the vehicle hull at predetermined intervals toaccommodate a plurality of individual blast deflectors or an individualblast deflector having a length complimentary of the vehicle length. Theblast deflector apertures may be equipped with countersinks 31, 33,respectively, to accommodate a shearable fastener 29, which may athreaded bolt 27. The fastener may be threadably engageable by mountingapparatus 25, which is engaged in apertures 42 to detachably affix theblast deflector in place on the vehicle structure. It is alsocontemplated that deflector may be detachably affixed to the vehiclestructure by a restraint.

The blast deflector legs may also be oriented relative to each other byan angle θ chosen to compliment the vehicle hull design so that theblast deflector may accommodate a given hull shape and, when affixedthereto, impart blast deflection along the length of the deflector. Thedeflector is shown as being hollow, but it could also be filled withplastic, glass, composites, metals or other energy absorbing blastdeflecting material. It also contemplated to be configured to haveinternal divisions to create individual spaces to dissipate the blast,or even be solid.

The sides of the deflector may intersect at vertex 24 which is shown asa sharp point, but which may, in other embodiments, be rounded. Thesides of the deflector may straight, or they may be arcuate, with eithera concave or convex orientation, as seen in FIGS. 2B and 2C,respectively.

As depicted in FIG. 2A, the base 20 may be equipped with an aperture 19which is aligned with counterbore aperture 17 at vertex 24. It iscontemplated that a sensor 11 may be accommodated within the counterboreaperture and accessible through aperture 19 of the blast deflector totransmit data regarding blast force, blast acceleration, blast velocityor any other parameter desired by the vehicle operators. It isunderstood that this described sensor arrangement may also be present inthe blast deflector configurations of FIGS. 2B and 2C. In anotherembodiment, it is contemplated that a shearable fastener may extendthrough the aperture to the vehicle structure to detachably affix theblast deflector to the vehicle structure.

FIG. 3 is a detail view sectional of the vehicle structure undersideshowing apertures 42 arranged on either side 48, 50 of the vehiclestructure centerline 46 at predetermined spaced intervals along itslength L. While the apertures on sides 48 and 50 are parallel to eachother, any arrangement of apertures may be contemplated to accommodateany arrangement of blast deflectors to the vehicle hull.

As previously mentioned, the apertures in the vehicle hull may bethreaded. A shearable bolt, rivet, or other fastener may be passedthrough the aligned aperture 30 in the blast deflector and aperture 42in the vehicle hull, to detachably affix the blast deflector onto thevehicle structure. As previously stated, the apertures may be equippedwith mounting apparatus to detachably affix the fastener into thevehicle hull. The fasteners may be of a material designed to shear offin response to blast force, thereby permitting the blast deflector to bedetached during the blast event but after it has dissipated the blastforce. In some embodiments, the connection may before from friction stirwelding. In some embodiments, mechanical connections are made throughplates, bolts such as shear bolts, insert plates and other connectingstructures. In one embodiment, insert plates are attached to the lowerhull. Different bolt thicknesses and a different number of bolts in theconnection can lead to different separation characteristics in a blastevent, as well as different patterns of energy absorption anddissipation through bolt shearing. The bolts may have varying diameters,and may be “tuned” to shear at various forces. Bolts shearing in acontrolled manner may dissipate blast energy and protect occupants inthe vehicle during a blast event.

FIGS. 4 through 8 depict various blast deflectors according to severalembodiments attached to different vehicle structures 14. In eachembodiment, the blast deflector is placed in position on the structureto dissipate the blast energy across a wide section of the vehicle hull.The blast deflector uses a small radius approximating a sharp edge closeto the ground to split the blast force of an IED , buried mine or otherexplosive, and direct significant energy away from the protectedstructure. It is understood that trading standoff for shape can bebeneficial and can reduce energy transmitted into the vehicle structure.Many “V” shaped structures have a flat or radiused bottom and fail tocome to a sharp point. As seen in FIGS. 4-8, the vehicle structureshapes tend to vary from flat to rounded to bowl shaped. Even if thevehicle structure is generally V shaped, the vertex of the vehiclestructure's V is not sharp, but rather is rounded. The addition of theblast deflector according to the present disclosure shapes blast energyattenuation away from the vehicle structure underside, the vehiclestructure itself, and the vehicle occupants. The blast deflector isdetachably mounted and even if the force of the blast shears thefasteners, the blast deflector dissipates the force of the blast. Theblast deflector also adds strength and rigidity, and transfers the blastenergy along the entire length of the vehicle hull.

As seen in FIGS. 9A through 9D, simulated blast data showed beneficialand unexpected results because of the optimized shape, material choice,cross sections and attachment methods as described. In the simulatedblast data, an IED is modeled and the blast deflector is simulated to bemade of the aforesaid materials.

FIG. 9A is a graphic representation of a vehicle without a blastdeflector subjected to a simulated IED blast showing the verticalacceleration over time and a test vehicle having a blast deflectoraccording to one embodiment of the disclosure. The simulated data isfiltered, and compared to a vehicle without a blast deflector. In bothFIGS. 9A and 9B, the IED is oriented so the simulated blast force occursin the center of the vehicle hull such that the blast deflectorencounters a blast force approximately equally on both sides of thedeflector. Specifically, in FIG. 9A, axis 52 is acceleration and axis 54is time. Line 56 depicts the acceleration over time of a vehicle hullwithout a blast deflector and line 58 depicts the acceleration over timeof a vehicle hull with a blast deflector. It is seen by reference to thesimulated blast results that the initial acceleration of the vehiclehull without a blast deflector is expected to be much higher than thatof a vehicle hull with the blast deflector. The difference in initialacceleration is important to vehicle and occupant survivability anddemonstrates that the blast deflector is expected to dissipate the blastforce of the IED. There is a reduction in peak acceleration and time topeak in center blast. This is reinforced by reference to FIG. 9B whereinthe vertical velocity of the vehicle 60 is charted against time 62. Line64 is the vertical velocity of an unprotected vehicle after an IEDexplosion, and line 66 is the vertical velocity of the vehicle with ablast deflector in place. These simulated results demonstrate that theblast deflector decreases the vertical velocity of a vehicle after anIED detonation.

FIG. 9C is a graphic representation of a vehicle subjected to asimulated IED blast showing vertical and lateral acceleration of thevehicle over time. In this test, the IED is oriented such that the blastforce is offset relative to the blast deflector. Specifically, axis 68is acceleration, and axis 70 is time. Line 72 is the is the verticalacceleration over time of the vehicle without a blast deflectorsubjected to an IED blast force, and line 74 is the verticalacceleration over time of the vehicle with a blast deflector that issimulated to be subjected to an IED blast. As seen in FIG. 9D, line 76is the lateral acceleration of the vehicle without a blast deflector andline 78 is the lateral acceleration of the vehicle with a blastdeflector in place. There is an expected improvement in offset blast.

The simulated data seen in FIGS. 9A-D demonstrate there is no change invehicle structure deflection. As seen in the simulated data, the blastdeflector detaches from the vehicle structure. The following simulatedresults are expected:

-   -   a. Z Acceleration is expected to be reduced    -   b. Center blast—shows a significant reduction; in a center        blast, the blast forces are symmetrical and the deflector may        remain attached to the vehicle    -   c. Offset blast—shows a significant reduction

Although the steps of the above-described simulated data have beenexemplified as occurring in a certain sequence, such processes could bepracticed with the steps performed in a different order. It should alsobe understood that certain steps could be performed simultaneously, thatother steps could be added, or that certain steps could be omitted. Inother words, the descriptions of the simulated data are provided for thepurpose of illustration, and should not limit the claimed invention.

Accordingly, it is to be understood that the above description isintended to be illustrative and not restrictive. Many embodiments andapplications other than the examples provided would be apparent uponreading the disclosure. For example, embodiments of the blast deflectormay be made to separate from the hull structure, or remain on the hullstructure. Also, the blast deflector attachment method can be varied, soas to time the separation of the blast deflector to the hull structureearlier or later in the blast event, to achieve different energyabsorbing and/or acceleration and/or velocity characteristics withdifferent shapes, thicknesses, and material choices.

The scope of the invention should be determined with reference to theappended claims along with the full scope of equivalents. It is intendedthat future developments will occur, and that embodiments of thedisclosed systems and methods will incorporate and be incorporated withsuch future developments.

Use of singular articles such as “a,” “the,” “said” together with anelement means one or more of the element unless a claim expresslyrecites to the contrary.

1. A blast energy deflector, comprising: a generally triangular bodyhaving a base affixed to an existing vehicle structure; the deflectorhaving two sides that intersect at an apex; the deflector being formedwith the base and the two sides as a closed form and being hollow alonga length of the vehicle structure; each the side extending beyond thebase to form legs; the blast deflector configured to be detachablysecured to the vehicle structure; the legs oriented at an angle toaccommodate the vehicle structure so that the deflector may accommodatethe vehicle structure shape and, when affixed thereto, impart blastdeflection along the length of the vehicle structure; and wherein thelegs each have a plurality of apertures, wherein each aperture has acounter sink.
 2. (canceled)
 3. The blast energy deflector of claim 1,wherein the triangular body is filled with plastic, glass, composites,metals or other blast deflecting material.
 4. The blast energy deflectorof claim 1, wherein the triangular body is configured to have internaldivisions to create individual spaces to dissipate the blast.
 5. Theblast energy deflector of claim 3, wherein the deflector is formed as asolid due to the filled-up material.
 6. The blast energy deflector ofclaim 1, wherein the apex is rounded.
 7. The blast energy deflector ofclaim 1, wherein the sides are straight.
 8. The blast energy deflectorof claim 1, wherein the sides are arcuate.
 9. The blast energy deflectorof claim 1, wherein the blast deflector is configured to be detachablyaffixed to the vehicle structure.
 10. The blast energy deflector ofclaim 1, wherein at least a portion of the deflector has a triangularform.
 11. A vehicle with a blast energy deflector system for a vehiclestructure, comprising: at least one blast deflector having a generallytriangular body with a base affixed to the existing vehicle structure;the deflector having two sides that intersect at an apex; each the sideextending beyond the base to form legs; the legs oriented at an angle toaccommodate the vehicle structure so that the deflector may accommodatethe vehicle structure shape and, when affixed thereto, impart blastdeflection along a length of the vehicle; and wherein the legs each havea plurality of apertures, wherein each aperture has a counter sink,wherein the deflector is formed with the base and the two sides as aclosed form and is hollow along the length of the vehicle.
 12. Thevehicle with a blast energy deflector system of claim 11, wherein theblast deflector is detachably affixed to the vehicle.
 13. (canceled) 14.The vehicle with a blast energy deflector system of claim 11, whereinthe triangular body is filled with plastic, glass, composites, metals orother blast deflecting material.
 15. The vehicle with a blast energydeflector system of claim 11, wherein the triangular body is configuredto have internal divisions to create individual spaces to dissipate theblast energy.
 16. The vehicle with a blast energy deflector system ofclaim 14, wherein the blast deflector is formed as solid due to thefilled-up material.
 17. The vehicle with a blast energy deflector systemof claim 11, wherein the blast deflector apex is rounded.
 18. Thevehicle with a blast energy deflector system of claim 11, wherein theblast deflector sides are straight.
 19. The vehicle with a blast energydeflector system of claim 11, wherein the blast deflector sides arearcuate.
 20. The vehicle with a blast energy deflector system of claim11, wherein a plurality of blast deflectors are affixed to the vehiclestructure.
 21. The blast energy deflector of claim 1, furthercomprising; a lower aperture formed at vertex having a counterbore; anda sensor accommodated within the counterbore of the lower aperture, thesensor configured to transmit data regarding at least one of blastforce, blast acceleration, and blast velocity.
 22. The vehicle with ablast energy deflector system of claim 11, further comprising: a loweraperture formed at vertex having a counterbore; and a sensoraccommodated within the counterbore of the lower aperture, the sensorconfigured to transmit data regarding at least one of blast force, blastacceleration, and blast velocity.